I am using the API to spin up a droplet that uses a custom image. I have enabled private ip at the time of creation but no network is created in the droplet. I can see in the DigitalOcean control panel that private networking is enabled and an ip is assigned but nothing in the VM.

Do I need to do something with cloud-init/user_data?

This is the result of ifconfig inside the droplet. The private ip is reported as 10.138.228.115 in the DO control panel.

cni0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1450
        inet 10.42.0.1  netmask 255.255.255.0  broadcast 0.0.0.0
        inet6 fe80::6cd8:2ff:fead:197c  prefixlen 64  scopeid 0x20<link>
        ether 6e:d8:02:ad:19:7c  txqueuelen 1000  (Ethernet)
        RX packets 16493  bytes 5822810 (5.8 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 14985  bytes 5568640 (5.5 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ens3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 138.197.215.166  netmask 255.255.240.0  broadcast 138.197.223.255
        inet6 fe80::2861:54ff:fecb:cf11  prefixlen 64  scopeid 0x20<link>
        ether 2a:61:54:cb:cf:11  txqueuelen 1000  (Ethernet)
        RX packets 22260  bytes 195862505 (195.8 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 14195  bytes 3272184 (3.2 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ens4: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet6 fe80::c047:b9ff:fec5:a9d2  prefixlen 64  scopeid 0x20<link>
        ether c2:47:b9:c5:a9:d2  txqueuelen 1000  (Ethernet)
        RX packets 14  bytes 1056 (1.0 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 17  bytes 1486 (1.4 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

flannel.1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1450
        inet 10.42.0.0  netmask 255.255.255.255  broadcast 10.42.0.0
        inet6 fe80::a05c:1dff:fe85:35e1  prefixlen 64  scopeid 0x20<link>
        ether a2:5c:1d:85:35:e1  txqueuelen 0  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 7 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 54328  bytes 16474969 (16.4 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 54328  bytes 16474969 (16.4 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

veth18f05a6b: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1450
        inet6 fe80::6c14:c2ff:fe3d:7b59  prefixlen 64  scopeid 0x20<link>
        ether 6e:14:c2:3d:7b:59  txqueuelen 0  (Ethernet)
        RX packets 16  bytes 1188 (1.1 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 60  bytes 4496 (4.4 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

veth2172da13: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1450
        inet6 fe80::8894:11ff:fef8:b374  prefixlen 64  scopeid 0x20<link>
        ether 8a:94:11:f8:b3:74  txqueuelen 0  (Ethernet)
        RX packets 3875  bytes 356564 (356.5 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 3945  bytes 950682 (950.6 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

veth9cf7a2ae: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1450
        inet6 fe80::b004:27ff:feea:198d  prefixlen 64  scopeid 0x20<link>
        ether b2:04:27:ea:19:8d  txqueuelen 0  (Ethernet)
        RX packets 5315  bytes 4296860 (4.2 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 4185  bytes 2032236 (2.0 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

vethb375b810: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1450
        inet6 fe80::401:77ff:fe2a:995d  prefixlen 64  scopeid 0x20<link>
        ether 06:01:77:2a:99:5d  txqueuelen 0  (Ethernet)
        RX packets 4033  bytes 370761 (370.7 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 4057  bytes 1286040 (1.2 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

vethe08e53f8: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1450
        inet6 fe80::f8cc:e5ff:fe3b:48ed  prefixlen 64  scopeid 0x20<link>
        ether fa:cc:e5:3b:48:ed  txqueuelen 0  (Ethernet)
        RX packets 2839  bytes 769892 (769.8 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2862  bytes 785522 (785.5 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0